From: David Miller <davem@xxxxxxxxxxxxx> Date: Tue, 11 Dec 2012 13:30:58 -0500 (EST) > > You cannot do this. > > After your changes the driver no longer does any TX flow control. > > It never stops the TX queue and never wakes it up later. > > It just drops packets on the floor when it runs out of descriptors. > > This breaks everything, and in particular packet schedulers and > TCP. > > I'm not applying this. And yes I mean that the "fail_tx" path of the transmit method is bogus too. You can't signal "out of descriptors" and stop the queue after the fact. NETDEV_TX_BUSY is for handling exceptional and extraordinary conditions, not for the normal queue full handling. You have to stop the queue before you run out of descriptors. When the queue is not stopped, you are telling the core networking that you absoultely will be able to successfully queue a packet and enough descriptors are available. This means the other CPDMA driver needs to be reworked too. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
